Effects of treadmill exercise on weight cycling in female mice

Weight cycling increases food efficiency and rate of weight regain. This study induced weight loss in adult female B6D2F1 mice via dietary energy restriction and exercise to determine whether the weight loss regimen influenced rate of weight regain. Four groups of animals were studied: RES, restricted (food restricted); EX, exercised (treadmill exercised); SC, sham control (treadmill exposure, not exercised); LC, lab chow control (appropriately aged control). Both EX and SC voluntarily reduced food intake to the level of the RES animals. The RES group showed increased food efficiency and rate of weight regain relative to the LC group; this effect was attenuated in both the EX and SC groups. These findings demonstrate that a) the cycling phenomenon occurs in mice, and b) stressors such as forced exercise or exposure to a novel environment can modify the pattern of food efficiency and rate of weight regain engendered by dietary restriction.